JP6143302B2 - Safety device for fall prevention stopper at tailgate - Google Patents

Description

  In the present invention, in order to load and unload cargo on a loading platform such as a truck, in a tailgate (loading platform lifting device) mounted on the rear or side of a truck or the like, a floor plate (loading platform) on which cargo is placed is mounted. The present invention relates to a fall prevention stopper provided.

  A truck bed, which is a vehicle for cargo transportation, is mounted on a chassis frame extending over the entire length of the truck, and there is a considerable difference in height between the bed floor and the ground surface. Since this hinders loading and unloading of cargo, a tailgate is well known for placing cargo on a floor plate and moving it up and down between the ground surface and the cargo bed floor using power such as hydraulic pressure. The tailgate is attached to the rear end portion of the truck, and includes a parallel link mechanism that moves up and down while keeping the floor plate in a horizontal state so as to prevent cargo or the like on the floor plate from falling. There is a case where the tailgate is installed on the side surface of the vehicle, and there is also a lifting device that supports the floor plate so as to be slidable on a vertical support and moves up and down horizontally between the ground surface and the loading platform floor surface.

  When loading and unloading cargo on a loading platform using a tailgate, a cargo cart with wheels (casters) is often used and loaded on a floor plate for cargo handling operations. The tip of the floor plate of the tailgate is equipped with a fall prevention stopper that serves as a wheel stopper for a wheeled cargo cart mounted on the floor plate that moves up and down, and is called a roll stopper (or caster stopper). Yes.

A tailgate having a floor plate and a fall prevention stopper installed at the tip of the floor plate will be described with reference to FIGS.
Two types of tailgates are widely used: one that stores the floor plate leaning against the rear end of the loading platform when not in use, and the other that stores the floor plate under the floor in the rear part of the loading platform with the floor plate folded. . The tailgate shown in FIG. 8 is a tailgate stored under the floor of the vehicle. The foldable floor plate 1 includes a main plate 11 and a sub plate 12 coupled by a double hinge. The end on the base side is connected to the parallel link mechanism 2. The floor plate 1 and the parallel link mechanism 2 are attached to the attachment portion 4 to the vehicle body by the support base 3. In the case of this tailgate, the attachment portion 4 is a guide rail, and the support base portion 3 is slidable forward when stored.

  When the tailgate is used for loading and unloading cargo, as shown in FIG. 8A, the floor plate 1 is expanded so that the upper surface of the main plate 11 and the sub plate 12 form a continuous plane. . Here, when an unillustrated lifting / lowering hydraulic cylinder mounted on the parallel link mechanism 2 is expanded / contracted, the floor plate 1 is positioned at the same height from the landing position (solid line in FIG. 8A) to the floor surface of the loading platform. The robot moves up and down while maintaining the horizontal state (two-dot chain line in FIG. 8A). Further, at the landing position, the main plate 11 can be pivoted (tilted), and the tip of the sub-plate 12 can be grounded as shown in FIG. 8B.

In order to load cargo onto the loading platform using the wheeled cargo cart, the cargo cart DL is placed on the floor plate 1 with the tip of the sub-plate 12 grounded. A drop prevention stopper 5 that can be switched between a standing position and a flat position is attached to the tip of the sub-plate 12. When the cargo cart DL is placed, the fall prevention stopper 5 is raised as shown in the figure. As a position, it hits the wheel of the cargo carriage DL. Then, the parallel link mechanism 2 is actuated by the lifting hydraulic cylinder to raise it to the height of the floor of the loading platform. During this time, the fall prevention stopper 5 keeps the standing position and prevents the cargo carriage DL from moving or dropping.
On the contrary, when unloading the cargo from the loading platform of the vehicle, the floor plate 1 is lowered and brought into contact with the wheels of the cargo cart DL in contact with the fall prevention stopper 5 at the standing position. Next, when the floor plate 1 is tilted to the state shown in FIG. 8B, the fall prevention stopper 5 is stepped on with a foot to switch to the flat position and move the cargo carriage DL to the ground. When safety is ensured, the fall prevention stopper 5 may be switched to the flat position when the floor plate 1 is sufficiently lowered and brought into contact with the ground (the position indicated by the solid line in FIG. 8A). Japanese Patent No. 3886308 discloses a mechanical safety device that holds the fall prevention stopper in an upright position until the floor plate is grounded in an elevating device that supports the floor plate on a vertical column.

An example of a fall prevention stopper for the tailgate will be described with reference to FIG. 9A is a perspective view of a state in which the main plate 11 and the sub plate 12 are unfolded, and FIGS. 9B and 9C are cross-sectional views taken along line AA in a state in which the position of the fall prevention stopper is switched. is there.
A drop prevention stopper 5 extending substantially across the entire width in the lateral direction is installed at the tip of the sub-plate 12, and the fall prevention stopper 5 is placed at a flat position at both side ends that do not hinder cargo handling work. A switching mechanism 5C for switching to the standing position is provided. In the flat position shown in FIG. 9B, the fall prevention stopper 5 is accommodated in the recess 5 </ b> R at the tip of the sub-plate 12, and its surface forms a flat surface with the upper surface of the sub-plate 12. Further, the fall prevention stopper 5 is pivotally attached to the end of the recess 5R so as to be rotatable about 5O, and toward the standing position shown in FIG. 9C by the standing spring 5S which is a linear spring. It is energized.

  A locking member 5X is fixed to the surface of the fall prevention stopper 5, and a lock member 5Y pivotally attached to the base portion 5B is provided at a position facing the rear end portion. When the front end of the lock member 5Y is rotated upward, the contact with the rear end of the locking member 5X is released, and the fall prevention stopper 5 is brought into the upright position by the upright spring 5S to generate a wheel stop function. When the lock member 5Y is tilted forward in advance and the fall prevention stopper 5 is stepped on, the lock member 5Y automatically comes into contact with the locking member 5X of the fall prevention stopper 5 as shown by a two-dot chain line in FIG. The fall prevention stopper 5 is locked in a flat position. Such a fall prevention stopper is disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-106675 according to the prior invention of the present applicant.

  The fall prevention stopper in FIG. 9 is installed at the front end of the folding floor plate in the underfloor retractable tailgate, but the same fall prevention stopper is stored with the floor plate leaning against the rear end of the loading platform. It is also used for standing tailgates. However, the floor plate of the standing type tailgate is generally a single plate, and has a structure that can rotate around the upper connection point of the parallel link mechanism when stored.

Japanese Patent No. 3886308 JP 2012-106675 A

  The fall prevention stopper installed on the tailgate is operated by an operator to switch between a standing position and a flat position when loading and unloading cargo. The operator usually operates the position of the fall prevention stopper with his / her foot while supporting the cargo cart with his / her hand. However, if the floor plate is still in a high position and the operator steps in the fall prevention stopper by mistake, the fall prevention stopper will be flat. Cargo carts may fall in position, causing damage to cargo in the cart and damage to surrounding equipment. In particular, if the operator unknowingly steps on the fall prevention stopper and does not notice that it has been locked in the flat position, the danger increases.

In Patent Document 1, in a lifting device provided with a floor plate supported by a vertical column, mechanical safety is maintained so that it cannot be switched to a flat position even if the fall prevention stopper is depressed until the floor plate lands. An apparatus is described. However, this safety device detects the landing of the floor plate mechanically with a lever and enables the release prevention stopper to be released. Even if the floor plate reaches a sufficiently low position, it is not yet grounded. The drop prevention stopper cannot be released to allow the cargo cart to pass through. Therefore, for example, when cargo is loaded and unloaded by placing a floor plate at a slightly higher position than the ground surface, it is impossible to use a cargo cart.
The object of the present invention is to provide a safety device that does not release the fall prevention stopper (switch to the flat position) when the ground level of the floor plate is high, to prevent the danger caused by the falling of the cargo carriage, and to release the fall prevention stopper This is to make the height easily adjustable.

In view of the above problems, the present invention provides an electric actuator provided with a blocking means for preventing the fall prevention stopper installed at the tip of the floor plate being lifted and lowered by a lifting device having a parallel link mechanism. And this is controlled by a detecting means attached to the parallel link mechanism. That is, the present invention
"A fall prevention stopper installed at the tip of a cargo loading floor plate that is installed in a vehicle having a cargo bed and is raised and lowered between the ground surface and the cargo bed floor surface by a lifting device,
The lifting device includes a parallel link mechanism that moves up and down while maintaining the floor plate in a horizontal state, and the parallel link mechanism includes an arm member coupled to the floor plate,
The fall prevention stopper is configured to be switchable between a standing position and a flat position, and
A blocking member that is actuated by an electrical actuator to block the fall prevention stopper from being in a flat position is provided, and a detection unit that detects the position of the arm member of the parallel link mechanism is provided,
The actuator is controlled according to the output of the detection means so as to prevent the fall prevention stopper from being in a flat position when the floor plate is above a predetermined height. ''
It is a fall prevention stopper characterized by this.

  According to a second aspect of the present invention, the fall prevention stopper is pivotally mounted in a recess formed at the tip of the floor plate, and is urged to an upright position by an upright spring. It is preferable that the blocking member is inserted into the recess when the fall prevention stopper is prevented from being in a flat position.

  According to a third aspect of the present invention, the detection means is preferably a proximity sensor that magnetically detects the position of the arm member of the parallel link mechanism.

  According to a fourth aspect of the present invention, the floor plate is pivotally attached to the arm member of the parallel link mechanism and is stood and stored at the rear end of the loading platform when not in use. May be. In the case of being stood and stored, a stop member for switching the floor plate to be inclined at a position in the vicinity of the cargo bed floor surface is often installed, but in this case, as described in claim 5, It is preferable that the operation of the blocking member is canceled when the stop member is switched to the inclined position of the floor plate.

The fall prevention stopper to which the present invention is applied is installed at the front end of a floor plate that moves up and down while maintaining a horizontal state by a parallel link mechanism. The fall prevention stopper is configured to be switchable between a standing position and a flat position. In the standing position, the fall of the cargo cart is prevented and the danger caused by the fall is avoided.
The fall prevention stopper of the present invention is provided with a blocking member for blocking the flat position from the standing position, and is held in the standing position by the blocking member when the floor plate is higher than a predetermined height. When the floor plate is still at a high position, this blocking member functions as a safety device that does not switch from the standing position even if an operator accidentally steps on the fall prevention stopper, and prevents the cargo cart from falling.

In the fall prevention stopper of the present invention, the blocking member for blocking the switching is actuated by an electric actuator, and the actuator is controlled by the detecting means for detecting the position of the arm member of the parallel link mechanism. The height of the floor plate is uniquely determined depending on the position of the arm member of the parallel link mechanism, whether it is stored under the floor or stood. Therefore, the height of the floor plate can be easily detected by detecting the relative position of the arm member of the parallel link mechanism with respect to the fixed portion (such as the support base in FIG. 8) using a proximity sensor or a microswitch.
Thus, in the fall prevention stopper of the present invention, the blocking member is controlled using an electric actuator in accordance with the signal of the height of the floor plate, so that the fall prevention stopper is allowed to be in a flat position (a safety device is installed). The height of the floor plate to be released can be set freely. For example, even if the floor plate is not grounded, it can be set so that the cargo cart can pass when it reaches a low position.

  The invention of claim 2 has a structure in which the fall prevention stopper is pivotally mounted in a recessed portion formed at the tip of the floor plate and is urged to a standing position by a standing spring, and is accommodated in the recessed portion in a flat position. When preventing the fall prevention stopper from being in the flat position, the blocking member is inserted into the recess. Since the fall prevention stopper accommodated in the recess and urged to the standing position by the standing spring is conventionally used, the fall prevention stopper according to claim 2 is reliable and operates at the same time. This structure is convenient when a blocking member for the fall prevention stopper is added.

  When a proximity sensor that performs magnetic detection is used as the detection means for detecting the position of the arm member of the parallel link mechanism as in the invention of claim 3, the position of the arm member can be detected in a non-contact state. Therefore, it becomes excellent in terms of reliability, durability, and the like.

  The invention according to claim 4 applies the present invention to a fall prevention stopper for a floor plate stood and stowed at the rear end of the loading platform, and the floor plate in this case can be rotated by the arm member of the parallel link mechanism. When retracted, it is raised vertically by a hydraulic cylinder or manually and leaned against the rear end of the loading platform.

By the way, the floor plate that is stowed and stowed is not a foldable type and is generally composed of a single plate, and is tilted with its tip lowered at a position near the cargo bed floor surface where the floor plate is at a high position. There are many things that can be done. This is done by loading and unloading cargo with a cargo cart by bridging the floor plate to the platform (freight loading port raised to the floor of the warehouse, etc.) provided at the distribution center and warehouse where cargo is collected. For this reason, it is called a transfer plate mechanism. In the stowable retractable floor plate, a stop member called a swing damper that is in contact with the lower part of the base side of the floor plate pivotally attached to the arm member is installed, and the position of the stop member is adjusted. Thus, the floor plate is switched between a horizontal state and an inclined state for the transfer plate mechanism (see FIG. 4 described later).
The invention according to claim 5 releases the operation of the blocking member when the stop member is switched to the inclined position of the floor plate, that is, when the floor plate is used as a transfer plate mechanism. Thereby, although the floor plate is at a high position, the fall prevention stopper is in a flat position, and cargo can be loaded and unloaded by the cargo cart between the platform and the loading platform of the vehicle.

It is a figure which shows the outline | summary of the tailgate which has the fall prevention stopper of this invention. It is a perspective view of the tailgate of FIG. It is a figure explaining the action | operation of a floor plate. It is an operation | movement figure of the floor plate which performs a delivery board mechanism. It is a perspective view which shows the blocking member of the fall prevention stopper of this invention. It is sectional drawing and the operation | movement figure of the blocking member of the fall prevention stopper of this invention. It is an operation | movement detailed drawing of the blocking member of the fall prevention stopper of this invention. It is a figure which shows the outline | summary of the conventional tailgate and the fall prevention stopper. It is a figure which shows the detail of the conventional fall prevention stopper.

  Hereinafter, a safety device for a fall prevention stopper according to the present invention will be described with reference to the drawings. The tailgate of the embodiment described here is a stowable retractable floor plate, and the floor plate is of a single plate, but the basic operation of the lifting device equipped with the parallel link mechanism and the fall prevention stopper The basic structure and the like are not different from the underfloor retractable tailgate of FIG. 8, and in the description of the present invention, the same reference numerals are given to the components corresponding to the parts of the structure of FIG. .

As shown in FIG. 1, which is a schematic diagram of the operation of the tailgate, in the tailgate of this embodiment, a floor plate 1 composed of one plate is connected to a parallel link mechanism 2, and the other end side of the parallel link mechanism 2 is It is pivotally attached to the support base 3. Since the tailgate of FIG. 1 is a stowable retractable type, the support base 3 is directly fixed to the mounting portion 4 (chassis frame) of the vehicle body by a mounting bracket (see also FIG. 2).
The parallel link mechanism 2 includes an upper arm 2U and a lower arm 2L as arm members, and also includes a lifting hydraulic cylinder OC. When the elevating hydraulic cylinder OC is expanded and contracted, the floor plate 1 moves up and down while maintaining a horizontal state from the landing position to a position where the floor plate 1 is level on the floor surface of the cargo bed, similarly to the tailgate of FIG. . At the landed position, the floor plate 1 can be inclined to ground the tip. Then, the tailgate of FIG. 1 is a bridge that inclines the floor plate 1 at a position near the cargo bed floor surface and bridges the floor plate 1 to the platform PL, as represented by a two-dot chain line in FIG. A plate mechanism (details will be described later) is added.

  In addition, the tailgate of FIG. 1 is provided with a bumper BP that prevents the vehicle from entering under the floor when another vehicle collides from behind. As shown in FIG. 2, the bumper BP is divided into three parts, and each divided piece is fixed to the support base 3 of the tailgate by a bar-like member extending in the front-rear direction of the vehicle body. The arm members 2U and 2L are configured to pass through. A power unit PU that houses a hydraulic pump that operates the lifting hydraulic cylinder OC and the like and a control device is attached to the support base 3.

  A fall prevention stopper 5 capable of switching between a standing position and a flat position is mounted on the front end portion of the floor plate 1 (see also FIG. 2). As shown in FIG. 1 (a), when the floor plate 1 is at a high position, the fall prevention stopper 5 is abutted against the wheel of the cargo cart DL to prevent the cargo cart DL from moving or dropping. Although illustration is omitted, a locking member similar to that of FIG. 9 is also installed to lock the fall prevention stopper 5.

  The fall prevention stopper 5 of FIG. 1 which is an embodiment of the present invention will be described in detail later, but enters the lower side of the fall prevention stopper 5 to prevent it from becoming a flat position from the standing position. A blocking member 6 (see FIG. 5) is provided. The blocking member 6 is actuated by an electric actuator to enter the fall prevention stopper 5, and even if the operator accidentally steps on the fall prevention stopper 5 until the floor plate 1 reaches a sufficiently low position, It prevents it from being flat. The predetermined height allowing the flat position can be set to an arbitrary position by setting the electric actuator, and is not limited to the position where the floor plate 1 has landed, but as indicated by H in FIG. In addition, it may be a position that has not yet landed.

The electric actuator that operates the blocking member 6 is controlled according to the position of the arm member of the parallel link mechanism 2 connected to the floor plate 1. As shown in FIG. 2, a proximity switch SW that magnetically detects the approach of an object is attached to the rod-like member for fixing the bumper BP. The proximity switch SW is an upper portion that passes through the gap of the bumper BP. When the approach of the arm 2U is detected and the upper arm 2U approaches, a signal is output to the electric actuator to allow the flat position. By changing the position of the proximity switch SW, the height of the floor plate 1 serving as the release position can be adjusted.
In the tailgate shown in FIG. 2, the proximity switch SW is attached to the rod-like member to directly detect the position of the arm member. However, depending on the case, a detection magnetic body attached to the bracket may be provided on the arm member.

In the embodiment shown in FIG. 1, there is provided a transfer plate mechanism that tilts the floor plate 1 and bridges it to the platform PL. When the transfer plate mechanism is used, the blocking member 6 of the fall prevention stopper 5 is released. . This will be described in detail with reference to FIGS.
FIG. 3 shows a state in which the floor plate 1 is stood and stored at the rear end of the loading platform when the tailgate is not used. As shown in the enlarged view of the connecting portion between the floor plate 1 and the parallel link mechanism 2, the floor plate 1 is pivotally attached to the connecting point CU of the upper arm 2U and can be rotated around the connecting point CU. By actuating the standing cylinder TC, the floor plate 1 is raised. In addition, a bracket that connects the floor plate 1 to the parallel link mechanism is provided with a stop member (swing damper) SD that serves as a rotation stopper for the floor plate 1, which is in a lateral position (solid line in the enlarged view of FIG. 3). And a vertical position (two-dot chain line in the enlarged view of FIG. 3). A second proximity switch SW ′ is placed in the vicinity of the stop member SD in that state so as to detect that the stop member SD is in the vertical position.

The stop member SD is set to the horizontal position as shown in FIG. 4A when the cargo is unloaded and the floor plate 1 is lifted and lowered. A plate-side stopper 1S is fixed inside the floor plate 1, and the plate-side stopper 1S comes into contact with the end surface of the stopper member SD that is in the lateral position when the floor plate 1 rotates. As represented by the two-dot chain line in FIG. 4A, the floor plate 1 is horizontal in this state.
When using the transfer plate mechanism, as shown in FIG. 4B, the stopper member SD is set in the vertical position. Thereby, the floor plate 1 can be rotated until the plate-side stopper 1S comes into contact with the so-called lateral surface of the stop member SD, and the front end can be inclined downward, as indicated by 2 in FIG. The floor plate 1 can be bridged between the loading platform and the platform PL as indicated by a dotted line.

  In the tailgate of the present invention, as shown in FIG. 3 and FIG. 4, the second proximity switch SW ′ for detecting the stop member SD in the vertical position is placed. The blocking member 6 is released. Therefore, when using the transfer plate mechanism, the fall prevention stopper 5 is switched to the flat position and the cargo carriage DL is used between the loading platform and the platform PL even though the floor plate 1 is at a high position near the loading platform. The cargo handling work that had been carried out becomes possible.

Next, the structure of the blocking member 6 provided on the fall prevention stopper 5 of the present invention will be described.
FIG. 5 is a perspective view of the concave portion 5R to which the fall prevention stopper 5 is attached in a state where the fall prevention stopper 5 is in the standing position so that the outline of the blocking member 6 of the present invention can be understood. 6 is a cross-sectional view (a) of the fall prevention stopper 5 and a plan view (b1, b2) showing the operating state. In FIG. 6 (a), the fall prevention stopper 5 in the standing position is shown by a two-dot chain line. Is shown.

As shown in these drawings, the fall prevention stopper 5 is pivotally mounted in the recess 5R at the tip of the floor plate 1 by a hinge 5H. The hinge 5H is one in which one hinge piece 5H1 is fixed to the back surface of the fall prevention stopper 5, and the other hinge piece 5H2 is fixed to the bottom surface of the recess 5R, and both hinge pieces are separated from each other. A torsional force is applied in such a direction by an internal spring (not shown). Therefore, the fall prevention stopper 5 is urged by a spring so as to be in the standing position in the free state, like the stopper of FIG.
A rectangular parallelepiped block 5B is fixed to the rear surface of the end of the fall prevention stopper 5 adjacent to the hinge 5H. The block body 5B has a thickness that is just accommodated in the recess 5R when the fall prevention stopper 5 is stepped on with a foot to a flat position.

  And the locking device 60 provided with the blocking member 6 is placed further on the end side than the block body 5B. The blocking member 6 is accommodated in the casing 61 and can slide in the direction of the block body 5B. In order to slide the blocking member 6, a lever 62 having a long hole is provided, and the lever 62 is connected to an output lever of the electric actuator 64 by a rod 63. The locking device 60 composed of these components is disposed at two L portions of the floor plate 1 shown in FIG.

Here, the operation of the blocking member 6 and the locking device 60 provided in the fall prevention stopper 5 of the present invention will be described.
In the cargo loading / unloading operation using the tailgate, when the floor plate 1 is at a high position, the blocking member 6 is moved to the lower side of the block body 5B by the operation of the electric actuator 64 as shown in FIG. 6 (b1). Even if it enters and the fall prevention stopper 5 is stepped on, it does not become a flat position. When the floor plate 1 reaches a sufficiently low position as shown in FIG. 1B, that is, when the predetermined height H is reached (or when the transfer plate mechanism is used), the proximity switch SW (or SW ′) This is detected, and the electric actuator 64 rotates the lever 62 to move the blocking member 6 to a position where it does not interfere with the block body 5B as shown in FIG. 6 (b2). As a result, the fall prevention stopper 5 can be accommodated in the recess 5R to be in a flat position, and the cargo cart DL can be passed.
It is also possible to urge the operator to recognize the situation by placing a warning light such as an LED in the recess 5R and lighting the fall prevention stopper 5 when it is in the standing position. Instead of the warning light, an audio warning device may be provided.

FIG. 7 shows a mechanism for sliding the blocking member 6. This figure is a bottom view of the blocking member 6 housed in the casing 61 as viewed from below.
A pressing spring 65 that urges the blocking member 6 toward the protruding direction (blocking position) is installed in the casing 61. On the back surface of the blocking member 6, a wall surface 6A orthogonal to the sliding direction of the blocking member 6 and a holding wall surface 6B opposite to the wall surface are formed. A pin 66 fixed to the lower part of the shaft abuts.
When the lever 62 is at the position shown in FIG. 7A (corresponding to the position shown in FIG. 6B1), the blocking member 6 is pushed by the pressing spring 65 and protrudes below the block body 5B. When the lever 62 is rotated in the arrow direction by the electric actuator 64, the pin 66 pushes the wall surface 6A. Therefore, when the lever 62 reaches the position shown in FIG. 7C (corresponding to the position shown in FIG. 6B2) through the state shown in FIG. 7B, the blocking member 6 has a blocking action. The position is released, and the fall prevention stopper 5 can be set to a flat position.

  As described above in detail, in the present invention, in the floor plate that is lifted and lowered by the lifting device having the parallel link mechanism, the fall prevention stopper installed at the tip of the floor plate is released when the floor plate is at a high position. A blocking member is provided to prevent this, and this is controlled by detection means attached to the parallel link mechanism. In the above embodiment, a rotary actuator is used as the actuator that operates the blocking member. However, for example, an actuator that reciprocates by an electromagnetic solenoid can also be used. Further, as a blocking member, various modifications are made to the embodiment, such as placing a plate member whose posture is changed to a vertical position (high height) and a horizontal position (low height) below the fall prevention stopper. Obviously it is possible.

DESCRIPTION OF SYMBOLS 1 Floor plate 2 Parallel link mechanism 2U Upper arm member 2L Lower arm member 3 Support base 5 Fall prevention stopper 5B Block body 6 Blocking member 64 Electric actuator SW, SW 'Proximity sensor

Claims (5)

A fall prevention stopper installed at a front end of a cargo loading floor plate that is installed in a vehicle having a loading platform and is lifted and lowered between the ground surface and the loading platform floor surface by a lifting device,
The lifting device includes a parallel link mechanism that moves up and down while maintaining the floor plate in a horizontal state, and the parallel link mechanism includes an arm member coupled to the floor plate,
The fall prevention stopper is configured to be switchable between a standing position and a flat position, and
A blocking member that is actuated by an electrical actuator to block the fall prevention stopper from being in a flat position is provided, and a detection unit that detects the position of the arm member of the parallel link mechanism is provided,
The actuator is controlled according to the output of the detecting means so as to prevent the fall prevention stopper from being in a flat position when the floor plate is at a predetermined height or more. The fall prevention stopper is pivotally mounted in a recess formed at the tip of the floor plate and is urged to a standing position by a standing spring, and is configured to be accommodated in the recess in a flat position.
The fall prevention stopper according to claim 1, wherein when the fall prevention stopper is prevented from reaching a flat position, the prevention member is inserted into the recess. The fall prevention stopper according to claim 1 or 2, wherein the detection means is a proximity sensor that magnetically detects a position of an arm member of the parallel link mechanism. The said floor plate is pivotally attached to the arm member of the said parallel link mechanism so that rotation is possible, and when not in use, it leans against the rear end of the said loading platform, and is stored in any one of Claims 1 thru | or 3. Fall prevention stopper. The elevating device is provided with a stop member for switching the floor plate pivotally attached to the arm member of the parallel link mechanism so that the floor plate is inclined at a position near the cargo bed floor surface,
The fall prevention stopper according to claim 4 which cancels operation of said blocking member when said stop member is changed to the position where said floor plate inclines.